RFR: 8365626: (fs) Improve handling of broken links in Files.isSameFile() (win)

[Alan Bateman]

On Thu, 4 Sep 2025 00:30:52 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

> Improve handling of broken symbolic links in `Files.isSameFile` on Windows as was done on Unix by the fix of [JDK-8154364](https://bugs.openjdk.org/browse/JDK-8154364).

src/java.base/windows/classes/sun/nio/fs/WindowsFileSystemProvider.java line 424:

> 422:     // contains file attributes and its handle
> 423:     // the attributes' key is valid as long as the handle remains open
> 424:     private record AttrsAndHandle(WindowsFileAttributes attrs, long handle) {}

"the handle remains open" is important. If I read the change correctly then the handle is closed at each step, thus invalidating (in the sense that the file key may be recycled) the entries in the set. I think the closes will need to be done in bulk, in a finally block.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27079#discussion_r2325082952